Calipers



Nov. 24, 1925- A. NELSON CALI PERS Filed May 2l, 1925 Patented Nev. 24, icas.

ANDREW NELSON, OF SALTFLEET TOWNSHIP, WENTWORTH COUNTY, ONTARIO,

CANADA.

CALIPERS.

Application filed May 21, 1925.

To all zu/0m t may concern.'

Be it known that ANDREW NnnsoN, a subject of the King of Great Britain, residing in Saltfleet 'fownship, in the county of YVentworth and Province of' Ontario, Canada, has invented certain new and useful Improvements in Calipers, of which the following' is a specification.

My invention relates to improvements in calipers and more particularly to the type of calipers used for laying out work rather than those used merely for measuring purposes.

Accurate setting of calipers for laying out work is extremely difficult principally for the reason that the finding finger usually misses its mark because of the jerky movement of the fingers caused by the necessary tightness of the swivel joint.

The notch 21, in order to provide the necessary tension for the pointer 16, is preferably oblique, and therefore diverges away from the planeof the finger 12, thus diverting the movement of the pointer outwardly from the plane of the finger as well as laterally from the center line of the same. By reason of this notch being thus oblique, thepointer at all times tensionally abuts the inner edge of sai-d notch, thereby affording constant rigidity; whereas, if the notch were parallel to the plane ofthe finger the pointer would have the obvious tendency of being otherwise than constantly rigid at all positions along the notch.

TheV principal object of the present invention is to provide means for finally setting the calipers to minute measurement or adjustment after the finding finger is set in close proximity or as nearly as possible to the mark.

A second important object is to provide a device of the class specified which will be simple, durable, effective, and inexpensive to manufacture.

These, together with other objects, may be atta-ined by the construction, combination and arrangement as will be hereinafter more fully described, illustrated in the accompanying drawing, and ascertained in the claims hereunto annexed.

Referring to the drawing:

Figure 1 is a front elevation of the calipers constructed in accordance with this invention;

Figure v2 Vis a rear elevation of the Same;

Serial No. 31,818.

Figure 3 is a side elevation of the construction shown in Figures 1 and 2; and

Figure t is an enlarged detailed view of the end portion of the finding fingers tipped Calipers used for lay out work and usu ally formed of a blunt ended setter finger and a shorter finding finger provi-ded with a pointer or needle, and it is to this type of caliper this invention'relates.

On the drawing the setter finger is indicated by and the finding finger by 12, and these two fingers are connected by the usual swivel joint 14 and adjusted as to their -degree of relativ rigidity by the set screw 15.

The setter finger 10 is usually curved as shown, although the invention is equally applicable to the class of `calipers having a straight setter finger.

The finding finger 12 is pointer or needle 16, and passed through an opening in a stud bolt 17 which is permanently secured to the said finger, and a knurled nut 19 is tightened against this pointer which. is adapted to abut the finger as shown, and thus the pointer is adjustably maintained at the required position longitudinally relative to the said finger.

The free end of the finding finger 12 is bent at right angles to the main portion to form a lip 2Oi and this lip is provided with an elongated notch 21 through which the pointer 16 passes. Also formed on the free end of the finger 12 is aright-angle triangular flange 22 disposed at one side of the nger and extending from the main portion thereof and abutting the corresponding edge of the lip 20. Through this fiange is threaded a set screw 23, and this set screw engages the pointer 16 so that by revolving the Set screw the pointer may be sprung back and forth along the notch 21 radially of its own axis according to which direction the said set screw is revolved.

The preliminary measurement is obtained by setting the setter finger 10 upon a determined point and then increasing or decreasing the gap lbetween the two fingers until the pointer A,16 is approximately upc-n provided with a this pointer is the other point. Assuming now that the gap between the two fingers is: approximately equal to the distance between the two points to be measured, the nal or accurate measurement is obtained by moving the pointer 16 back or forth by means of the set screw 23.

In this type of calipers, there ably provided a small tip 2l on the end of the finger l0, adapted to extend over the surface of the work while the remainder of the end of the finger engages the side of the work, so as to prevent said finger from slipping.

There has thus been provided a simple and efiicientdevice of the class described and for the purpose specified.

I-Iaving now fully and completely described the invention and the manner in which it is to be performed, I claiinz 1. In a pair of calipers including a first finger and a second finger pivoted together, a lip formed on the free end of the second finger and having an elongated notch, a yieldable point-er carried by said finger and extending through said notch, and means for slightly bending the pointer in relation to the centre lineof said finger, said pointer being adapted to move along said notch while being thus bent.

2. In a pair of calipers including a first finger and a second finger pivoted'togethei', a lip formed on the free end of the second is preferfinger and having an elongated oblique notch, a yieldable pointer carried by said finger and extending through said notch,

and means for slightly bending the poiinei: in relation to the centre line of said finger, said pointer being adapted to move along said notch while being thus bent.

3. In a pair of calipers including a first finger and a second finger pivoted together, a lip formed on the free end of the second finger and having an elongated notch, a yieldable pointer carried by said finger and extending through said notch, a flange formed on one side of the saine finger, and a set screw threaded through said flange and engaging the pointer, said set screw being adapted by being turned in alternate directions to slightly bend the pointerin relation to the centre line of said finger and thus move it back and forth along said notch.

a. In a pair of calipers including a first finger and a second finger pivoted together, an ofl'set tip on the free end of the hrst linger so as to form a shoulder on said end, a yield-able pointer carried by the second finger, and means for slightly bending the pointer so that its position relative to said finger is alterable.

ln testimony whereof I have affixed my signature.

ANDREW NELSON. 

